The aim of this work is to investigate common-rail injector behavior towards multiple injection strategies. A numerical model has been developed to simulate the electro-fluid-mechanic behavior of a Bosch mass production injector (standard injector) and validation against experiments has been performed. In order to make the injector performing multiple injections, a deep investigation has been numerically carried out. The numerical study highlighted different areas where injector may be improved with particular emphasis on electronic driving circuit. A new driving circuit concept, previously developed, has been successfully simulated showing promising fast-response capability for injector actuation.